Glass.



STAIBES PATENT op nion.

EUGENE G. SULLIVAN AND WILLIAM C. TAYLOR, OF CORNING, NEW YORK, ASSIGNOBS TO CORNING"GLASS WORKSQOF CORNIN'G, NEW YORK, A CORPORATION OF NEW YORK.

GLASS.

I 1,151,911. Specification of Letters Patent.

- No Drawing.

To all whom it may concern:

Be it known that we, EUGENE C. SULLIVAN and WILLIAM C(TAYLOR, both citizens of the United States of America, and residents of GorningfNew York, have invented certain new and useful Improvements in Glass, of which the following is a specification.

Our invention relates to a certain new and useful glass which is especially adapted for perfect union with metallic parts subjected J linear co-efficient of expansion'varying between. .000012 and .000017.

A glass for the purpose named, in addi tion to having a proper co-efficientof expansion must be soft and relatively stable, possess good vitrification, and must moreover for some of the above uses, remain viscid or pasty through a relatively wide range of temperature in order topermit its proper working and" manipulation inthe formation of the bulb or tubing, and the subsequent tr watment thereof. By softness, we refer to the character of glass, whenheated, of flowing, which property maybe expressed by the temperature (as measured on the centigrade scale) at which a suspended thread of the glass heated through about half'its length elongates of its own weight through a given distance (5. 6. one millimeter) ina given time (i. 6. one minute) Stability has reference to the resistance of glassto' chemical at tack, while vitrificationhas reference to the behavior of the glass when worked in a flame or from the melting pot.

We have found that a glass prepared by the following formula has, to a high degree, the desirable properties above named, the

proportions stated being analytic i. e. those;

Patented Aug... 31, 1915.

Application filed Octobei 27, 1918. Serial No. 797,647.

of the glassitself. Thus stated, our inven tion is embodied in its most perfect form in a glass havmg the-following composition A glass formed from the above composition has a linear co-eificient of expansion as measured in the above terms of .0000135 and a hardness of 630 C. t

A less perfect glass has the following composition This glass, however, is harder than that givenin the first named formula, it being 636. 0., and its expansion CQ-QfliClGllt is We have discovered that, generally speak ing, the substitution of one per cent of AL -O for two per cent. of SiO ,wh1le ralsing the expansion of co-eficientof-the glass, does not eii'ect the hardness and leaves that unchanged. Henoe, the application of th1s rule to either of the above glass mixtures per.-

mits a variation in the expansion co-eficient f through a relatively wide range while ma1nand one-half per cent, the alumina and silica'being interchangeable for each other in the proportions stated.

3. A glass comprising about forty-two per cent. silica, about nineteen per eent. barium and alkali.

4. A glass comprising about, forty-two per I cent. silica,- about nineteen per cent. soda,

about five per cent. potash, about nineteen per cent. barium oxid, anti about fifteen per cent. alumina.

In testimony," whereof we have hereunto signed our names 1n the presence of two wit H nesses. 01nd, and about fifteen per cent. alumnae,

V EUGENE C. SULLIVAN.

WM. C. TAYLOR. Witnesses:

FRED. GCAMBON, G. WILLIS DRAKE. 

